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Now that I have my K2 connected again for computer control I have found that a few things in KComm that worked with the K3 don’t work with the K2 because the control commands, though they may look the same, don’t all work the same way on both radios. So I spent yesterday evening fixing the problems.

One of the things that didn’t work was the auto-repeat option for CQ calling. I was testing it by sending a CQ on 30m with just 1W output into the magnetic loop in the attic. I didn’t expect anyone to come back to me, and no-one did, but I was surprised that my signal was spotted in Northern Spain by EA1GFY. The effectiveness of that magnetic loop antenna never fails to amaze me.

I don’t think many people use as little as 1W on PSK31 but it would be interesting to see what you could work with such low power. It seems to me that 1000 miles per watt should be perfectly achievable. I’ve made a few contacts using the K2 and 4 or 5 watts over similar distances to what I’d expect using the K3 and 40 watts. I think conditions, more than power, determine how far you can work. More power just makes it easier.

On Sunday Olga and I went for a walk in the Lakes. As Olga doesn’t like climbing my Wainwright activation possibilities were limited so I decided to head for Rannerdale Knotts, LDW-209, the fifth from lowest Wainwright.

Despite its low height, Rannerdale Knotts looks quite forbidding. The most direct path is very steep. However the summit is also accessible by an easy walk up the valley named Rannerdale which brings you on to a ridge that leads directly to it. On the way there are great views back over Crummock Water and Loweswater out to the Solway estuary.

Just as we were about to climb on to the ridge I heard Phil G1OPV/P calling from the summit of Mellbreak (the hill on the left in the above picture.) Though only a couple of miles away I could only just hear him due to the steep ground between us. I hurried to the top to make contact and agree to work again when I reached the summit of Rannerdale Knott for a true summit-to-summit.

I had barely reached the summit and was still getting my breath back when I heard a “CQ WOTA” call and made contact with M0AYB/P (also Phil) who was on Dodd, another fairly low fell beside Bassenthwaite Lake. Anyone who knows the area was surprised that VHF signals could travel between two such low hills with a large mass of mountains in between. Olga captured me making the contact with Phil on her camera. I was using the Motorola GP300 on this occasion, with 4W out to a 5/8 wave telescopic “Black Whip” antenna. In my left hand you can see the Olympus personal voice recorder I use for logging.

After signing with Phil I was immediately called by Geoff, G4WHA/P who had arrived on the Causey Pike, the summit I climbed a few weeks earlier and failed to recognize or activate! Whilst I sneaked up on it the back way making it easy to reach, Geoff tackled it by the direct route which he informed me had turned out to be tougher than he anticipated. Accompanying Geoff on his first Wainwright outing – a baptism of fire – was Mark M1MPB/P so I made two contacts with the same summit. Then I contacted Phil G1OPV/P again to make the summit to summit with Mellbreak. I suspect we could have made the contact by shouting if the wind had been in the right direction, in fact I think I could just see Phil silhouetted against the skyline on the summit.

After that I was called by Robert M3XJV/P who was on Birkhouse Moor, on his way to Helvellyn. This was a nice addition to my chaser total as the Helvellyn hills seem to be out of range of my home station in Cockermouth. Finally I made two contacts with home based stations: Roger G0MWE in Dearham and Ron G0UQC in Keswick before I was able to sit down and join Olga having our picnic lunch and enjoying the view over Buttermere.

 

We returned to the car via the precipitous direct descent down to the lake. It was a short walk but a successful one. Seven contacts including five summit to summits from a low fell that on previous visits (before WOTA) you would never expect to make a contact from. I think Wainwrights On The Air is transforming VHF activity in the Lake District and the comment from one activator that it is getting hard to find a clear frequency is proof of it.

News via the NUE-PSK email list that over the weekend George N2APB presented and demonstrated a prototype of the SDR Cube project at the TAPR Digital Communications Conference in Vancouver, WA near Portland, Oregon.

The SRD Cube’s formal title is “A Portable Software Defined Radio Utilizing An Embedded DSP Engine for Quadrature Sampling Transceivers” and it was devised by George Heron, N2APB and Juha Niinikoski, OH2NLT.

N2APB's SDR Cube

A companion to his NUE-PSK modem, it’s designed to provide “a standalone SDR transceiver (no PC required) that is quite portable and trail friendly”.

“So far the most attention has come from the SDR Cube’s “live bandscope” showing a +/- 4 kHz spectrograph of band activity along the top of the graphic display.  Some preliminary pics are on the start of the website … http://www.sdr-cube.com“.

From his earlier 11 September email where the SDR Cube was first announced:

“a totally self-contained embedded SDR transceiver using a Softrock for the RF front end and a pc board implementation of an HF modem that couples tightly with the NUE-PSK Digital Modem.  The Cube is designed to fit into a 4” x 4” x 4” pre-cut black powder-coated aluminum enclosure containing all controls, blue graphic display showing the familiar band scope of spectrum signals, and the popular Softrock RXTX v6.3 board.”

The latest update this morning from George is that the pricing “is not yet established … but soon will be.  I think the cost of the parts and pcbs is around $100, so you can guess what the corresponding price might be.”

They’re aiming for the range of offerings (bare PCB, kit, assembled & tested etc) to be available in about six weeks. As well the plan is for there to be a direct digital connection between the SDR Cube and the NUE-PSK by the shipping date. In the meantime check out the pics at http://www.sdr-cube.com. Also brief mention on WETNET.

UPDATE: George N2APB has posted some videos of the SDR Cube in action. There’s a 25′ overview and five shorter clips.

The sdr-cube.com website now (30 Sept 10) has much more information about the rig including hardware and software architecture diagrams, a photo gallery, a very detailed 26 page pdf of the TAPR DCC conference presentation (7.5MB) and this feature list.

• Standalone SDR transceiver … no PC, portable, compact
• Self-contained single band … based on the I/Q RF front end
• Softrock-compatible … designed to interface with SR v6.3 RXTX, etc.
• Low Power … 90ma (Cube), plus 100 ma (Softrock Rx) or 300 ma (Software Tx
• Add-on RF Amp & Attenuator … good control of incoming RF, optimize some SR features.
• Quadrature Sampling Clocking options … DDS, Si570, or I2C to target Softrock
• Built-in Keyer … 1-50 wpm, Iambic A, B, or straight key
• Popular HF modes … SSB, CW, AM, Digital (with special interface to NUE-PSK)
• Special interface to NUE-PSK Modem … digital interface provides best quality
• Graphic LCD Display … Provides clear indications of the many status and options
• Bandscope … provides +/- 4 kHz spectrum visibility for Rx, signal monitor for Tx
• Audio filtering … low corner 200Hz, high corners 700, 1500, 2400 or 3600Hz
• Audio Output … Headphones or amplified speaker, Binaural Audio
• Beeper … User interface clicks, code practice oscillator, and more
• Frequency agility … Fast/Med/Slo tune, dual VFOs, memories, RIT/XIT
• Menus … Calibration, all settings, system gain, sidetone frequency, etc
• Software Upgradeable … Bootloader enables user to load new software versions
• Open Source & Hardware

A new Yahoo Group has also been set up and info can be found at http://groups.yahoo.com/group/sdr-cube/.

LATER UPDATE: 14 Oct 2010 – Tobias DH1TW has posted a 75 minute interview with George N2APB on his website – complete with comprehensive ‘shownotes’.

I hadn’t been on D-STAR for a few days, but popped on for a quick chat this morning. I was particularly sorry to hear that GB7ML from Tring, as well as GB7AU are now QRT. I’m not entirely sure what has happened, although someone mentioned ‘politics’, but the current expectation is that the nodes will not return.

What a shame – GB7ML in particular had such fabulous coverage.

I installed a four port RS-232 serial card in my shack PC today. When I bought the computer earlier in the year I purchased and installed a two port serial card, thinking that would be enough. But it wasn’t. You can never have enough serial ports if you want to interface with radios. With four, I can now have CAT control of both the K2 and the K3, the TNC connection to the Kenwood TM-D710 and one more which is currently controlling the PTT of the FT-817 for the EchoLink node but could be used for the control port of the Kenwood if I ever decided to use that for EchoLink. No more hassles with USB to serial adapters, and all my USB ports are free for things like sound cards. I don’t know why people use laptops for shack computers, they provide far fewer options.

Needless to say, things did not go as smoothly as they could have done. I thought I could have COM2 for the K2, COM3 for the K3 which would be easy to remember. But Windows gave the ports the designators COM3, 4, 10 and 11. There’s an option to reassign the port numbers but Windows claimed that everything from COM2 to COM9 was in use. By what, was my unanswered question.

In the end I decided to name the ports COM2 through COM5 as I wanted regardless of Windows’ protestations. They did work, but finding out which port was which was a matter of attaching a radio to one socket, loading a program and trying all possible COM port numbers until it worked, as there was no logical correspondence between the numbering and the sockets on the back of the computer. Who said it was meant to be easy anyway?

Despite all this I managed to make a few contacts using JT65A on 20m including DU1GM, N0OB and K1CF, using 25W to the dipole.

Although I now have computer control of the K2 I don’t have a sound card interface as I have cracked open the plastic case of the USB audio dongle and superglued the bottom half containing the PCB to the stripboard on which I will be building my homebrew SignaLink clone. Of course, now I have a serial cable connection between the computer and the K2 I don’t need a VOX controlled interface, never mind an isolated one because the serial cable will bypass the isolation anyway!

David Rowe, VK5DGR, is working on Codec2, an open source low rate speech codec that is intended to replace the proprietary AMBE vocoder in D-STAR.  Bruce Perens, K6BP, discusses the Codec2 project here, and further information from VK5DGR is here.

If you missed it, I discussed the issues with proprietary technology and D-STAR here, here, and here.

If you believe open source technologies are crucial to amateur radio, please donate to the Codec 2 project.  Paypal donations are accepted.